An alien species has invaded polluted rivers. The unsightly creature fouls water, taints the landscape and crowds out native rivals. When dead and ruptured, it emits toxic gas that suffocates fish.

These claims are still under debate, or at least not yet proven, but they constitute a recent environmentalist narrative and popular impression about the fast-spreading invertebrate Pectinatella magnifica, commonly known as a bryozoan, or moss animal.

The primitive, gelatinous masses they form began to be spotted in the Geumgang River in mid-June. In less than a month, they were found in all of Korea’s four major rivers, thanks to searches by environmentalists.

The Internet and social media were flooded with disgusting images of them and damning indictments. One online reporter even wrote about how it tasted and how he got sick after eating it.

The exotic organism, which originated from North America, has been around in some lakes and reservoirs in Korea since the 1990s. Researchers, the government and fish farmers paid little attention to the animal. It is only one of a dozen freshwater bryozoan species here and is not thought to be harmful despite its ugly appearance.

But the animal suddenly became a hot political topic as environmentalists have made it a symbol of the harm done by the controversial Four Rivers Restoration Project led by former President Lee Myung-bak.

The nation’s most ambitious hydrological engineering project was completed in 2012 with the aim of cleaning up rivers, limiting floods and droughts, and developing areas for resorts, eco-parks and bicycle trails. It involved building 16 dams, dredging over 500 million cubic meters of riverbed sand and gravel, and widening water channels in the Hangang, Nakdonggang, Yeongsangang and Geumgang rivers.

Two years later, the 22 trillion won ($21 billion) project is widely considered a failure. Despite the huge sums of money spent on controlling pollutants, the water quality has little improved, and by some standards has even worsened.

Vast swaths of wetlands and sand dunes were lost and soil was eroded. A number of native species disappeared or became threatened while invasive plants and animals have proliferated. The financial burden from maintenance costs and debt placed on the state-run water developer involved in the work turned out to be far greater than initial estimates, not to mention the incalculable price society may have to deal with in the damage to ecological systems.

To conservationists, Pectinatella magnifica is clear evidence of environmental damage from altering the rivers. Little research has been done on the filter-feeding invertebrate but it is known to live in warm water, like low-speed currents and feed on algae. The dams installed during the project slowed the flow of the rivers and this year’s unusually long drought and hot weather have contributed to excessive algal blooms. Without natural enemies, Pectinatella magnifica could ruin the already fragile ecosystem balance, they warn.

But unlike their initial claim that it lives only in polluted environments, overseas reports and studies have shown that clean water is its preferred habitat. The argument that it contains a toxic substance has also been countered by research which says it is no more dangerous than other invertebrate species. Biologists even say it can clean up water by consuming toxic algae.

The results of the four rivers project have vindicated many of the environmentalists’ warnings. They had rightly emphasized that altering the waterways would harm rivers’ natural functions of purifying water, moderating floods, allowing fish to spawn and delivering nutrients and sediments to basins and deltas, which cannot be copied by man-made systems.

But intended or unintended, their unwarranted vilification of the moss animal and black-and-white logic are eroding their own credentials.

Some extreme ecologists have been criticized for disregarding unfavorable data, exaggerating risks and stoking unnecessary fear about technology. Their fixation on the Arcadian idealization of nature and prioritization of conservation at any cost have also undercut their causes and their appeal to the public.

During the four rivers project, they presented their own measures to address the water shortages, pollution and seasonal floods that plagued some localities. But their points were diluted in murky scientific uncertainties and disputes with development-oriented experts and officials. This resulted in a failure to forge an extensive popular movement to fight the political forces, mainstream scientists and business groups involved in the river project.

Korea needs more powerful, knowledgeable and responsible environmentalists to fight human hubris about subjugating nature. It is evident that the lessons from the four rivers debacle have not been learnt. Projects to build dams and develop riverside resorts are still underway in southern parts of the country. Those with vested interests are turning blind eyes to signs of ecological problems by the excessive intervention in rivers’ own rhythms, which evolved alongside the ecosystem for millennia.

It is true that man cannot live without rivers, which sustain life, grow crops and provide energy. But neither can rivers maintain their integrity and health without man, especially in this age of all-powerful science and planetary dangers from climate change.

As Albert Einstein observed, “We cannot solve problems by using the same kind of thinking we used when we created them.” A fundamental shift is needed in our thinking on how to balance river management for the needs of humans and nature in the long term.

This holds true to environmentalists. They should be equipped with the knowledge, ability and will to handle the whole complex systems of ecology, rather than fanning ungrounded dislike of a foreign species that is not as threatening to nature as human beings.

By Hwang Jang-jin

Hwang Jang-jin is the managing editor of The Korea Herald. He can be reached at jjhwang@heraldcorp.com. ― Ed.